Nanoparticles Loaded with Nitric Oxide Overcome Antibiotic-Resistant Skin Bacteria

A team of drug developers has successfully treated superficial wounds infected with antibiotic-resistant bacteria by using nanoparticles containing nitric oxide.

Nitric oxide (NO) is produced by many cells throughout the body and has several important biologic functions including killing bacteria, healing wounds, and increasing blood flow by dilating blood vessels. Utilizing NO as a therapeutic agent is difficult, however. "The problem is that nitric oxide is very short-lived, and until now, methods to deliver it to targeted tissues in the proper dosages have proven elusive," explained senior author Dr. Joel Friedman, professor of physiology, biophysics, and medicine at Albert Einstein College of Medicine (New York, NY, USA).

To get around this problem, investigators developed a novel type of nanoparticle that could store NO while dry and then slowly release it when exposed to moisture. To test these particles in an animal model, a population of mice suffering from skin infections caused by methicillin-resistant Staphylococcus aureus (MRSA) was used. For the study, the MRSA-mice were divided into three groups. One group was treated with the nanoparticles loaded with NO. A second group received nanoparticles lacking nitric oxide, while the third group received no treatment.

Results published in the April 23, 2009, online edition of the Journal of Investigative Dermatology revealed that a week after treatment wounds in the group treated with the NO-containing nanoparticles were significantly improved and smaller than lesions in the two other groups. Bacterial counts were significantly lower in the NO-treated group compared with the other groups, and the NO-treated group showed evidence of accelerated wound healing both visually and microscopically. There were no signs that the nanoparticles were in any way toxic to the animals.

These results encouraged the researchers to conclude that, "NO-releasing nanoparticles have the potential to serve as a novel class of topically applied antimicrobials for the treatment of cutaneous infections and wounds."

Related Links:
Albert Einstein College of Medicine